Rheostat.



A. J. HORTON.

RHEOSTAT. APPLICATION FILED FEB. 20. 1915.

Patented Oct. 26, 1915.

a z HWAVS an" H u UNITED STATES PATENT OFFICE.

ALB RT I ORTON, OE WHITE PLAINS, NEW YORK, ASSIGNOR To THE CUTLER-HAMMER MFG. 00., or MILWAUKEE, WISCONSIN, A CORPORATION OF wIsconsm.

RHEOSTAT.

Specification of Letters Patent.

Patented Oct. 26, 1915.

1 Application filed February 20, 1915. Serial No. 9,545.

To all whom it may concern:

Be it known that I, ALBERT J. HORTON, a citizen of the United States,residing at White Plains, in the county of Westchester and State of NewYork, have invented new and useful Improvements in Rheostats, of whichthe following is a full, clear, concise, and exact description,reference. being had to the accompanying drawing, forming a part of thisspecification.

This invention relates to rheostats.

One of the objects of the invention is to provide a simple, compact andeflicient rheostat for various uses, such for example, as lampregulation in connection with pathscopes.

A further Object is to provide a rheostat for concealed mounting withsupporting means permitting ready adjustment thereof to an accessibleposition for regulation, inspection, and so forth.

Other Objects and advantages of the invention will appear hereinafter inconnection with a description of the accompanying drawing whichillustrates a typical embodiment of the invention.

In the drawing, Figure 1 is a front view of the rheostat and mountingtherefor. Fig. 2 is an elevational view of the rheostat. Fig. 3 is aplan view thereof with the cover removed. Fig. 4 is a sectional view onthe line 44 of Fig. 3, and Fig. 5 is a sectional view on the line 5-5 ofFig. 3.

The rheostat illustrated is particularly designed for a pathscope and ispreferably mounted within a recess of the pathscope frame, as shown inFig. 1. structurally, the

,rheostat includes a plurality of sections of of the rheostat. Inpractice, also, said frame is slidably mounted on a standard 7 so thatthe rheostat is capable of travel thereon for a purpose hereinafter setforth.

The resistance elements comprise wires 8 of suitable gage wound spirallyon the supports 1 and 2 which latter are ofinsulating material such, forexample, as asbestos board. Each support carries a fixed resistance anda variable resistance, both of which for convenience are formed of acontinuous-resistor and both of which are preferably embedded within alayer of insulating cement 9. As mentioned, however, certain portions ofthe variable resistances are left uncovered by the cementitiousmaterial, as indicated at 10, for engagement by the controlling member5. It will thus be observed that the rheostat includes a definite amountof fixed reslstance and a variable resistance as is ordinarily desiredin the control of motion picture machines. As illustrated, the variableresistances on the two supporting bases are connected by the controllingmember 5 which constitutes a contact bridge, and the fixed resistancesare provided at their Outer ends with the terminals 11 for lineconnections. Thus, as shown, the resistances are connected in seriesrelation, although it will be understood that the same might beconnected in parallel if desired.

The controlling member 5 comprises two spring arms having cupped contactextremities in resilient engagement with the exposed resistance coils,at 10. Said spring arms are mounted upon a'member 12 fixed to a spindlel3 revolubly journaled in the frame 4 and extending at right anglesbelow the supports 1 and 2. The contact arms 5 are electricallyconnected together but are insulated from the member 12 by suitablemeans, such as an insulating bushing 14. The spindle 13 is also providedwith a right angled extension 15 which serves as a handle for Operatingthe controlling member. Pivotal movement of said controlling member inboth directions is limited by ofiset lugs 16 on the member 12 which abutthe base of the frame 4.

The supporting standard 7 of the rheostat is provided with two parallelrods 17 extending longitudinally thereof and the rests within a recess19 of a support 20, but may be readily withdrawn and rendered accessiblefor inspection and manipulation of its controlling. element. It may benoted in this connection that the concealed mounting of the rheostat asdescribed has distinct advantages such as, the normal concealment of itscontrolling member whereby accidental for unauthorized operation thereofis safeguarded.

To facilitate withdrawal of the rheostat fromits inclosure, the same ispreferably provided at its front end with a suitable hand grip 21.Further advantages of the structure described may also be mentioned,namely, that the rheostat may be Withdrawn from its inclosure duringoperation and thus exposed for better ventilation, and the heatgenerated thereby may be kept out of proximity to the working parts ofthe pathscope so that drying of the machine lubricant is avoided.

What I claim as new and desire to secure by Letters Patent is one end ofsaid frame, and said resistance having terminal connections adjacent theother end of said frame.

2. In a rheostat, a metallic supporting frame, a'pair of insulatingbases mounted thereon in spaced parallel relation, resistances on saidbases, a controlling member pivoted to said frame and movable over'alimited portion of said resistances, and a metallic cover for said basessecured to said fr'ame.

Copies of this patent may be obtained for iive cents each, by addressingthe "Commissioner of Patents;

3. In a rheostat, an elongated insulating base, a continuous resistanceelement coiled thereon, an insulating element adhering to said base andembedding a fixed portion of said resistance and exposing anotherportion thereof, and a controlling member movable over said exposedportion.

4. In a rheostat, an insulating support,

a resistor wound thereon to provide a fixed resistance and a regulatingresistance, and an msulatmg element entirely covering said fixedresistance and covering all but a limited area of said regulatingresistance. 5. In combination, a rheostat, an inclosingmember to supportthe same, and a standard fixed within said inclosing member and slidablysupporting said rheostat to render the latter adjustable in position.

6. In combination, a rheostat, a standard therefor slidably supportingthe same, and

an inclosing and supporting member having a recess to receive saidrheostat and stand ard, said rheostat having a normally concealedcontrolling member operable upon slidin withdrawal of the same from saidrecess 7,. In combination, an elongated rheostat having a fixedresistance at one end and a regulating resistance and controlling memberat the other end, and a standard arranged longitudinally of saidrheostat and slidably supporting the same at its fixed resistance endwhereby said rheostat is movable to clear its controlling member for operation.

In witness whereof, I have hereunto subscribed my name in the presenceof two wit- Washington, D. 0."

